According to a Tuesday blog post by CardCoins, the two firms have joined a list of crypto companies – including BitMEX, Bitfinex, OKCoin, and Xapo – that financially support developers who work on Bitcoin Core, the reference implementation of the Bitcoin software.

In the latest example, the two startups have collectively offered a one-year grant to Hennadii Stepanov, a Bitcoin Core contributor who has worked on the software's build system, networking stack, and general peer review for over two years. The grant will allow Stepanov to quit his university job and work on Bitcoin Core full-time, per the blog post.

"Funding for open source projects is traditionally derived from companies who benefit from that software, and CardCoins is no exception," said the blog post. "Bitcoin Core is an essential piece of our infrastructure. Without carefully tested ‘full-node’ software, neither the Bitcoin network nor our business would be possible."